The authors report the clinical, pathologic, and immunologic features of a case of jejunal cytotoxic/suppressor T-cell lymphoma associated with intractable malabsorption. Histologically, the tumor exhibited striking involvement of small bowel surface and glandular epithelium, and of epithelium in sites of disease dissemination. This epitheliotropism consisted of both cell clusters resembling Pautrier 's microabscesses and single cells within epithelium. Grossly, the jejunal mucosal fold pattern was completely obliterated by lymphoma which formed miliary nodules and multiple distinct tumor masses. Despite aggressive chemotherapy the patient developed widespread disease, and died 11 months after presentation. At autopsy, in addition to disseminated lymphoma, there was a notable activation of hematopoiesis evidenced by extensive extramedullary hematopoiesis and bone marrow hypercellularity. Many lymph nodes spared by the lymphoma showed a polyclonal proliferation of plasma cells and immunoblasts. In view of recent immunologic evidence that normal cytotoxic/suppressor T-cells selectively home to the gut surface epithelium, striking tumor cell epitheliotropism may be a morphologic marker for visceral lymphomas of cytotoxic/suppressor T-cell origin. This unique case broadens the clinical and morphologic spectrum of T-cell disorders.